For example, an automatic analysis device such as an automatic biochemical analyzer and an automatic immunoassay analyzer includes a washing tank for washing a probe with washing water after suctioning and discharging a reagent or a target specimen sample.
Generally, a level of contamination of the probe during suctioning of the reagent or the target specimen sample performed by using the probe is in a volume range of approximately 5 mm in which the probe is thrust into the reagent or the sample after the probe detects the liquid surface. Therefore, the range becomes a washing range of the probe. However, for example, in order to prevent evaporation of the reagent, when suctioning the reagent through the probe from a notched reagent bottle attached with a cap, the probe needs to be washed over a wide range corresponding to the range from the cap of the reagent to the bottom of the reagent bottle.
However, widening of the washing range of the probe results in a disadvantage described below. First, as the washing range is widened, a washing time needs to be sufficiently provided. In addition, after the probe is washed, a large quantity of washing water adhered onto a side surface of the probe remains. If a succeeding reagent is suctioned through the probe in such a state, it is assumed that the washing water adhered onto the side surface of the probe is mixed in the reagent bottle, thereby leading to dilution of the reagent caused by washing water.
Even in a case where the probe is thrust deep inside the target specimen sample, as described above, an equivalent disadvantage is caused due to the wide washing range of the probe.
Therefore, when the washing range of the probe is wide (example: a washing range of 80 mm), as a method of removing washing water adhered onto the side surface of the probe after the probe is washed, there is a known method of removing washing water adhered onto the side surface of the probe by moving the probe to a position of a vacuum suctioning tube after being washed at a probe washing position, lowering the probe into the vacuum suctioning tube, and evacuating the inside of the vacuum suctioning tube (PTL 1 and PTL 2).